// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef SKIA_EXT_BITMAP_PLATFORM_DEVICE_MAC_H_
#define SKIA_EXT_BITMAP_PLATFORM_DEVICE_MAC_H_

#include <stdint.h>

#include "base/compiler_specific.h"
#include "base/macros.h"
#include "skia/ext/platform_device.h"

namespace skia {

// A device is basically a wrapper around SkBitmap that provides a surface for
// SkCanvas to draw into. Our device provides a surface CoreGraphics can also
// write to. BitmapPlatformDevice creates a bitmap using
// CGCreateBitmapContext() in a format that Skia supports and can then use this
// to draw text into, etc. This pixel data is provided to the bitmap that the
// device contains so that it can be shared.
//
// The device owns the pixel data, when the device goes away, the pixel data
// also becomes invalid. THIS IS DIFFERENT THAN NORMAL SKIA which uses
// reference counting for the pixel data. In normal Skia, you could assign
// another bitmap to this device's bitmap and everything will work properly.
// For us, that other bitmap will become invalid as soon as the device becomes
// invalid, which may lead to subtle bugs. Therefore, DO NOT ASSIGN THE
// DEVICE'S PIXEL DATA TO ANOTHER BITMAP, make sure you copy instead.
class SK_API BitmapPlatformDevice : public SkBitmapDevice, public PlatformDevice {
public:
    // Creates a BitmapPlatformDevice instance. |is_opaque| should be set if the
    // caller knows the bitmap will be completely opaque and allows some
    // optimizations.
    // |context| may be NULL. If |context| is NULL, then the bitmap backing store
    // is not initialized.
    static BitmapPlatformDevice* Create(CGContextRef context,
        int width, int height,
        bool is_opaque, bool do_clear = false);

    // Creates a context for |data| and calls Create.
    // If |data| is NULL, then the bitmap backing store is not initialized.
    static BitmapPlatformDevice* CreateWithData(uint8_t* data,
        int width, int height,
        bool is_opaque);

    ~BitmapPlatformDevice() override;

    // PlatformDevice overrides
    CGContextRef GetBitmapContext(const SkMatrix& transform,
        const SkIRect& clip_bounds) override;

protected:
    BitmapPlatformDevice(CGContextRef context,
        const SkBitmap& bitmap);

    SkBaseDevice* onCreateDevice(const CreateInfo&, const SkPaint*) override;

private:
    void ReleaseBitmapContext();

    // Loads the current transform and clip into the context. Can be called even
    // when |bitmap_context_| is NULL (will be a NOP).
    void LoadConfig(const SkMatrix& transform, const SkIRect& clip_bounds);

    // Lazily-created graphics context used to draw into the bitmap.
    CGContextRef bitmap_context_;

    DISALLOW_COPY_AND_ASSIGN(BitmapPlatformDevice);
};

} // namespace skia

#endif // SKIA_EXT_BITMAP_PLATFORM_DEVICE_MAC_H_
